Microwave-assisted one-step synthesis of fenamic acid hydrazides from the corresponding acids

A facile and efficient method for synthesis of fenamic acid hydrazides from their acids in one-step reaction under microwave irradiation and solvent-free conditions was developed. Compared with the two-step conventional heating method, the process was simple, the reaction time was very short and the yields were almost quantitative.     

Scanning near-field IR microscopy of proteins in lipid bilayers

We use infrared near-field microscopy to chemically map the morphology of biological matrices. The investigated sample is built up from surface-tethered membrane proteins (cytochrome c oxidase) reconstituted in a lipid bilayer. We have carried out infrared near-field measurements in the frequency range between 1600 and 1800 cm(-1). By simultaneously recording the topography and chemical fingerprint of the protein-tethered lipid bilayer with a lateral resolution of 80 nm × 80 nm, we were able to probe locally the chemical signature of this membrane and to provide a local map of its surface morphology.     

Research and Development with Stock-Dependent Spillovers and Price Competition in a Duopoly

This paper investigates the research and development accumulation and pricing strategies of two firms competing for consumer demand in a dynamic framework. A firm’s research and development is production-cost-reducing and can benefit from part of the competitor’s research and development stock without payment. We consider decisions in a game characterized by Nash equilibrium. In this dynamic game, a player’s action depends on whether the competitor’s current research and development stock are observable. If the competitor’s current research and development stock are not observable or observable only after a certain time lag, a player’s action can be solely based on the information on the current period t (open-loop strategy). In the converse case, it can also include the information on the competitor’s reaction to a change in the current value of the state vector (closed-loop strategy), which allows for strategic interaction to take place throughout the game. Given the cumulative nature of research and development activities, a primary goal of this paper is to determine whether, regardless of the observability of the competitor’s current research and development stock, free research and development spillovers generate a lower level of scientific knowledge than research and development appropriability. A second objective of the paper is to determine how the observability of the rival’s current research and development stock affects a firm’s research and development and pricing decisions and payoffs under imperfect research and development appropriability.     

Ultra high amorphous silicon passivation quality of crystalline silicon surface using in‐situ post‐deposition treatments

A parametric study of post‐deposition hydrogen plasma treatment of intrinsic a:Si:H films is performed. We demonstrate a significant improvement in passivation of c‐Si(100) promoting epitaxy after an in‐situ hydrogen plasma treatment depending mainly on the pressure and slightly on the power. Plasma diagnostic indicates an increase of H_α* signal with high power and low pressure. However, our analysis reveals a better hydrogen incorporation with high pressure and a slight increase in monohydride with high power. Longer H₂ plasma duration up to 50 s shows no detrimental effect on the passivation quality. Optimizing the in‐situ H₂ plasma treatment, high minority carrier lifetime over 15 ms was achieved after short thermal annealing. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

Exploring Supramolecular Self‐Assembly of Tetraarylporphyrins by Halogen Bonding: Crystal Engineering with Diversely Functionalized Six‐Coordinate Tin(L)2–Porphyrin Tectons

This study targets the construction of porphyrin assemblies directed by halogen bonds, by utilizing a series of purposely synthesized Sn(axial ligand)₂–(5,10,15,20‐tetraarylporphyrin) [Sn(L)₂‐TArP] complexes as building units. The porphyrin moiety and the axial ligands in these compounds contain different combinations of complimentary molecular recognition functions. The former bears p‐iodophenyl, p‐bromophenyl, 4′‐pyridyl, or 3′‐pyridyl substituents at the meso positions of the porphyrin ring. The latter comprises either a carboxylate or hydroxy anchor for attachment to the porphyrin‐inserted tin ion and a pyridyl‐, benzotriazole‐, or halophenyl‐type aromatic residue as the potential binding site. The various complexes were structurally analyzed by single‐crystal X‐ray diffraction, accompanied by computational modeling evaluations. Halogen‐bonding interactions between the lateral aryl substituents of one unit of the porphyrin complex and the axial ligands of neighboring moieties was successfully expressed in several of the resulting samples. Their occurrence is affected by structural (for example, specific geometry of the six‐coordinate complexes) and electronic effects (for example, charge densities and electrostatic potentials). The shortest intermolecular I???N halogen‐bonding distance of 2.991 Å was observed between iodophenyl (porphyrin) and benzotriazole (axial ligand) moieties. Manifestation of halogen bonds in these relatively bulky compounds without further activation of the halophenyl donor groups by electron‐withdrawing substituents is particularly remarkable.     

Sonocatalytic degradation of methylene blue using spindle shaped cerium oxide nanoparticles

Journal of Solid State Electrochemistry - The industrial revolution has raised major concern of environmental pollution, due to excess release of hazardous chemical, dyes, etc. into water bodies....     

Use of Formic Acid as a CO Surrogate for the Reduction of Nitroarenes in the Presence of Dienes: A Two-Step Synthesis of N-Arylpyrroles via 1,2-Oxazines

Formic acid, activated by acetic anhydride and a base, was employed as a CO surrogate to deoxygenate nitroarenes to nitrosoarenes, a reaction catalyzed by a palladium/phenanthroline complex in the homogeneous phase. Nitrosoarenes were trapped by conjugated dienes to give 3,6-dihydro-2H-[1,2]-oxazines. The latter were then transformed into N-arylpyrroles employing CuCl as the catalyst. The reaction was designed to give the best results for pyrroles lacking any substituent in the 2 and 5 positions, which are difficult to produce employing most pyrrole syntheses.     

Dispersing behavior of recycled rubber particles

The hydrophobic nature of recycled rubber particles presently limits their use only in non-aqueous media. Recycled rubber particles were chemically modified by preparation of amphiphilic semi-interpenetrating polymer networks using poly(acrylic acid) as the hydrophilic polymer. The resulting composite particles are water dispersible and suitable for various aqueous media applications.